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Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.

GENERAL INFORMATION: 503-823-7404

1120 SW Fifth Ave, Suite 600, Portland, OR 97204

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LT2 (Long Term 2 Enhanced Surface Water Treatment Rule)

  • The Bull Run Watershed has a variance to the treatment requirements of LT2

    The Bul Run source has low levels of Cryptosporidium, resulting in a variance to the treatment requirements of LT2

An Introduction to LT2

The Long Term 2 Enhanced Surface Water Treatment Rule (LT2) was promulgated by the federal Environmental Protection Agency (EPA) to “reduce illness linked with the contaminant Cryptosporidium and other disease-causing microorganisms in drinking water.”

There are two major requirements of the LT2 rule that apply to Portland’s drinking water system:

  • Provide additional Bull Run source water treatment to specifically address Cryptosporidium – the Portland Water Bureau does not treat for Cryptosporidium; the State of Oregon issued Portland a variance for the source water treatment requirements of LT2 in accordance with federal and state law.  

The City advocates that EPA revise the source water monitoring requirements of the LT2 rule to incorporate recently developed genotyping methods for any detected Cryptosporidium species to provide more relevant public health information to water customers.


Uncovered Reservoirs

Portland's strategy for compliance with the uncovered finished drinking water reservoir requirements of LT2.

History of Portland's Legal Challenge

Description and documentation legal challenge to LT2.

Documents & Correspondence

This page contains documents and correspondence regarding compliance with LT2.